RE: [LEAPSECS] the legacy of ephemeris time

From: Seeds, Glen <Glen.Seeds_at_Cognos.COM>
Date: Mon, 22 Dec 2003 17:26:17 -0500

Hmm... there is certainly a problem when it comes to specifying legal time
referring to the future: sun time is not predictable into the future with a
high degree of precision. People wanting that kind of precision in legal
documents would have two choices:

1) Specify local time in a location and juristiction where local time is
legally determinable to high degree of precision within some specified prior
time (e.g., 6 months). UTC+fixed local offset (allowing for DST) could serve
this purpose, in juristictions where courts accepted it.

2) Use a uniform time scale, which would be disconnected from the sun. TAI
could serve this purpose. Parties would have to accept that the specified
time is not directly meaningful to humans. This would not be useful to most
people, but could be useful for contracts where precise duration is more
critical than human readability.

  /glen
-----Original Message-----
From: Leap Seconds Issues [mailto:LEAPSECS_at_ROM.USNO.NAVY.MIL]On Behalf
Of jcowan_at_REUTERSHEALTH.COM
Sent: December 22, 2003 4:20 PM
To: LEAPSECS_at_ROM.USNO.NAVY.MIL
Subject: Re: [LEAPSECS] the legacy of ephemeris time


Steve Allen scripsit:

> I assert that there is no need to disengage civil time from the sun
> just to satisfy the users of precision time. Is there any argument
> which can justify why civil time needs to be precise and uniform to a
> millisecond?

I believe there is. Disclaimer: I am *emphatically not* speaking for
my employer here.

Currently, the problem of simultaneous transactions in the world's financial
markets is handled by three things: 1s accuracy is considered good enough,
transactions are inherently serialized by individual market systems, and
distinct markets are not strongly coupled. None of these things is going to
persist, and that in a timescale of years, not centuries. In order to
correctly coordinate transactions in multiple markets, it will be necessary
to achieve subsecond accuracy in LCT -- LCT, because it is LCT that is legal
time.

--
It was impossible to inveigle           John Cowan
<jcowan_at_reutershealth.com>
Georg Wilhelm Friedrich Hegel           http://www.ccil.org/~cowan
Into offering the slightest apology     http://www.reutershealth.com
For his Phenomenology.                      --W. H. Auden, from "People"
(1953)
This message may contain privileged and/or confidential information.  If you
have received this e-mail in error or are not the intended recipient, you
may not use, copy, disseminate or distribute it; do not open any
attachments, delete it immediately from your system and notify the sender
promptly by e-mail that you have done so.  Thank you.
Received on Mon Dec 22 2003 - 14:27:03 PST

This archive was generated by hypermail 2.3.0 : Sat Sep 04 2010 - 09:44:54 PDT